Blood results show iron deficiency. What should I ask during my first hematologist visit?

Hi guys, 29F, I've been feeling unwell for a couple years - fatigue, brain fog, palpitations, breathlessness, always sleepy, etc. I have problems eating (psychological) and often under eat, I also eat a 90% vegetarian diet, and I can have fairly heavy periods. So I suspected iron deficiency and got tested for it, here are my results:

CBC: Haemoglobin 10.1 PCV 0.33 MCH 24 MCHC 29 Hypochromic RBCs

Iron Studies: Serum iron 6.5 Transferrin 3.36 TIBC 75.3 Saturation 8% Ferritin 6

Vit D 49 Folate not tested

I'm seeing a hematologist next week, I'm still learning about anemia and iron deficiency and the treatments etc. From your experiences, what are some things I need to keep in mind during this first visit? Some things I need to ask the doctor? Anything I should "reject" (e.g. my first general doc told me to just eat more spinach and beetroot to fix this...)? And finally, with these levels and assuming proper treatment, how long can I expect until I start feeling better? Thank you :)